Java/Security/JCE

Encrypting and Decrypting with the JCE

   <source lang="java">

import java.awt.Point; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.util.HashSet; import java.util.Random; import java.util.Set; import javax.crypto.Cipher; import javax.crypto.CipherInputStream; import javax.crypto.CipherOutputStream; import javax.crypto.SecretKey; import javax.crypto.SecretKeyFactory; import javax.crypto.spec.DESKeySpec; public class TestCipher {

 // Password must be at least 8 characters
 private static final String password = "zukowski";
 public static void main(String args[]) throws Exception {
   Set set = new HashSet();
   Random random = new Random();
   for (int i = 0; i < 10; i++) {
     Point point = new Point(random.nextInt(1000), random.nextInt(2000));
     set.add(point);
   }
   int last = random.nextInt(5000);
   // Create Key
   byte key[] = password.getBytes();
   DESKeySpec desKeySpec = new DESKeySpec(key);
   SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
   SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
   // Create Cipher
   Cipher desCipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
   desCipher.init(Cipher.ENCRYPT_MODE, secretKey);
   // Create stream
   FileOutputStream fos = new FileOutputStream("out.des");
   BufferedOutputStream bos = new BufferedOutputStream(fos);
   CipherOutputStream cos = new CipherOutputStream(bos, desCipher);
   ObjectOutputStream oos = new ObjectOutputStream(cos);
   // Write objects
   oos.writeObject(set);
   oos.writeInt(last);
   oos.flush();
   oos.close();
   // Change cipher mode
   desCipher.init(Cipher.DECRYPT_MODE, secretKey);
   // Create stream
   FileInputStream fis = new FileInputStream("out.des");
   BufferedInputStream bis = new BufferedInputStream(fis);
   CipherInputStream cis = new CipherInputStream(bis, desCipher);
   ObjectInputStream ois = new ObjectInputStream(cis);
   // Read objects
   Set set2 = (Set) ois.readObject();
   int last2 = ois.readInt();
   ois.close();
   // Compare original with what was read back
   int count = 0;
   if (set.equals(set2)) {
     System.out.println("Set1: " + set);
     System.out.println("Set2: " + set2);
     System.out.println("Sets are okay.");
     count++;
   }
   if (last == last2) {
     System.out.println("int1: " + last);
     System.out.println("int2: " + last2);
     System.out.println("ints are okay.");
     count++;
   }
   if (count != 2) {
     System.out.println("Problem during encryption/decryption");
   }
 }

}

      </source>